Adam pays $20 for 4 stickers and 2 marbles.
6 stickers cost as much as 2 marbles.
- How much is 1 sticker?
- How much is 1 marble?
- How much is 5 marbles and 4 stickers?
(a)
Choose the smaller group to be 1 u.
Cost of 6 stickers = Cost of 2 marbles
Cost of 3 stickers = Cost of 1 marble
Cost of 1 sticker = 1 u
Cost of 1 marble = 3 u
Cost of 4 stickers
= 4 x 1 u
= 4 u
Cost of 2 marbles
= 2 x 3 u
= 6 u
Total cost of 4 stickers and 2 marbles
= 4 u + 6 u
= 10 u
10 u = 20
1 u = 20 ÷ 10 = 2
Cost of 1 sticker = 1 u = $2
(b)
Cost of 1 marble
= 3 u
= 3 x 2
= $6
(c)
Cost of 5 marbles and 4 stickers
= 5 x 3 u + 4 x 1 u
= 15 u + 4 u
= 19 u
= 19 x 2
= $38
Answer(s): (a) $2; (b) $6; (c) $38